Google Maps Hacks by Berlin artist Simon Weckert is performance art at its best: not only for the artifact it creates (in the most ephemeral way, in form of a live data stream on Google Maps), but for the awareness it creates.
99 second hand smartphones are transported in a handcart to generate virtual traffic jam in Google Maps.Through this activity, it is possible to turn a green street red which has an impact in the physical world by navigating cars on another route to avoid being stuck in traffic.
As this piece of geeky awesomeness spreads around the world on social media, its most impressive impact is not the data hackers drooling over the ingenious act of carrying 99 smartphones through Berlin in a hand cart, but the stunning amount of people who for the first time understand how Google Maps sources their traffic data - by constant surveillance of billions of smartphone users.

The role of art in this world is to trigger social debate - with his rather straightforward hack, Weckert made a worthwhile contribution to educate people how the world around them (and the phone in their pocket) is truly wired.
A few years ago, I wrote about another surveillance-related piece of performance art: